Remained after the death of his parents without means of livelihood, two sisters (Justine and Juliette) trying to survive by all available means. At first, the women come to the monastery, the orders of which differ little from the brothel, and then in the brothel, little distinguishable from the monastery. The Justin is struggling to keep her maiden honor, constantly getting out of the frying pan into the fire, while Juliette calmly takes all the changes and prefer to use what nature had given...

. The main actor of Cruel Passion Martin Potter also played in Evil Heritage

Review: This is another adaptation one of the better Marquis de Sade stories "Justine" AKA "Cruel Passion" which tells the story of two sisters, Justine and Juliette, who are orphaned and expelled from their convent school. Juliette becomes a prostitute and rises to a position of power by freely indulging in vice. Her sister Justine, however, tries to remain virtuous and is victimized by nearly everybody. This film was adapted a number of times by European directors of the late 60's and 70's and then, strangely, never really touched again. The best adaptation was Jesus Franco's "Marquis de Sade's Justine" even though it was marred by the wretched over-acting of "name" American actors like Mercedes McCambridge and Jack Palance, and the wretched non-acting of "daughter of an American name" lead actress Romina Powers. It is nevertheless one of Franco's best movies. "Justine" with Alice Arno and the Swedish hardcore film "Justine och Juliette" were less successful; both are so drenched in graphic sex that they lose the fascinating spirit of de Sade, and ultimately any kind of coherent plot at all.
This film actually works pretty well for awhile and is quite faithful to the original story with only a few digressions into the then popular "nunsploitation" genre as in one lurid scene where Juliette makes it with one lesbian nun while her sister is nearly raped by another. The end is kind of abrupt, and not terribly effective though.
The lovely lead Koo Stark who plays the TITular character is definitely a real ASSet here, not because she was a great actress but because she was one of the few European sex stars who genuinely could portray an innocent character. (Some might describe her as a "girl next door" type, but few people were probably lucky enough to have a girl like HER living next door to them). The actress playing Juliette was actually pretty good, making it all the more regrettable that she kind of disappears halfway through the movie. And as others have said, there is also an early cameo appearance by another English cult actress, Glory Annen.
Not a great movie, but worth seeing I guess.